Bio-efficacies of different solvent extracts of Cosmos sulphureus on 3rd instar larvae of Aedes aegypti

Abstract

Mosquitoes are vector carriers of Dengue haemorrhagic fever, Malaria, Chikungunya, Yellow fever, Zika virus, Filariasis and Japanese encephalitis which are mainly found in tropical and sub-tropical countries. Mosquito borne disease have great impact on human health in terms of mortality and morbidity along with economic loss as per the survey conducted worldwide. The study of larvicidal activity of existing weeds mainly found on wastelands is very scanty. The potentiality of invasive weeds in controlling mosquito need to be explored on large scale. Hence, the present investigation was undertaken to evaluate larvicidal potential of different solvent crude (petroleum ether, chloroform, ethyl acetate, and methanol) of Cosmos sulphureus against 3rd instar larvae of Aedes aegypti L. Cosmos leaf extracts exhibited larval mortality with different solvents chloroform < ethyl acetate < methanol < petroleum ether with LC50 values as 2453.56 ppm, 4706.05 ppm, 5877.20 ppm and 8254.46 ppm respectively. In the results obtained chloroform extract has proved to be more effective than methanolic and ethyl acetate extracts. This study revealed that Cosmos sulphureus extracts in crude and pure formulations can further be used in controlling mosquitoes.